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Chainsaws & Size (probably again)

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This is a question for those of you who have large, professional saws, and use them on large diameter logs for bowl blanks.

I am currently using a Stihl with a 25" bar. It is a 59cc engine running at less than 5 hp. I need a bigger and more powerful machine.

What saw and bar length do you recommend?
 
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This is a question for those of you who have large, professional saws, and use them on large diameter logs for bowl blanks.

I am currently using a Stihl with a 25" bar. It is a 59cc engine running at less than 5 hp. I need a bigger and more powerful machine.

What saw and bar length do you recommend?
Im from logging country a stihl 59 cc with a 25 in bar is extremly maxed out. 20 inch is good for that saw 24 is for one ofs, cutting slow. Go to a stihl ms-661 7.2 bhp and then you can throw a 28 -36 in bar on .
 
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You're right Glen, though I didn't know why. My 362 with that 25" bar does cut real slow but I never thought about the possibility of being "maxed out". Now I wonder why they would offer that option?
 
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Tom, Another option is to port the exhaust on your Stihl. I did that on mine when I went from an 18" to 25" bar. It is easily done and there are multiple videos on youtube about doing it. It is simply allowing more exits for the exhaust. It gave the saw a noticeable power difference.
 
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If your going to modify the ports you might as well polish them and install a Teflon coated piston
and use racing fuel in the motor. :)
 
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I think I used the wrong terminology. There is a sheet metal shield over the exhaust that is used for noise suppression. By drilling holes in this shield it does make the saw louder but it also allows the exhaust to leave the engine faster and does increase the h.p. You do have to adjust the carb and the videos explain this. I watched a lot of videos and read everything I could find before I tried it myself. This modification seems to be widely known in the logging industry. I have run the saw for a year or more since these modifications and I'm happy with the results. I am not a motor mechanic so I suggest anyone considering this to do their own research.
There is a considerable leap in price and weight of a saw that is intended to use more than an 18" bar. The saws go from a "farm" saw to a logging or commercial saw and the prices increase considerably. I have used several logging saws and the overall weight of the saw becomes a consideration. My saw handles the larger bar with roughly the same power as it handled the 18" bar before the modifications.
 
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When anyone says their saw cuts slow, I ask about the chain. What tooth and raker combination are you using. Some of the new chains are called safety chain, and hardly take much of a curl at all. Ditch the safety chain, and go to a full chisel tooth. If you sharpen yourself, have you filled down the rakers? I've broken down a LOT of big urban trees. I have a Sthil 029 with a 20" bar and a Husqvarna 3120 with a 36" bar. The Husqvarna is a machine, 119 cubic centimeters, 8.3hp. You can set the bucking teeth and pull the handle with both hands!
 
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When anyone says their saw cuts slow, I ask about the chain. What tooth and raker combination are you using. Some of the new chains are called safety chain, and hardly take much of a curl at all. Ditch the safety chain, and go to a full chisel tooth. If you sharpen yourself, have you filled down the rakers? I've broken down a LOT of big urban trees. I have a Sthil 029 with a 20" bar and a Husqvarna 3120 with a 36" bar. The Husqvarna is a machine, 119 cubic centimeters, 8.3hp. You can set the bucking teeth and pull the handle with both hands!

Good thoughts on the chain configuration; that can make a tremendous difference.

You:
strongman-chainbreakbig_05.png
Me:
depositphotos_13983505-stock-illustration-cartoon-98-pound-weakling.png

I am in awe of you guys with your huge saws. I have two saws — my primary saw is a Makita 54cc with 18” bar, my second is an old Stihl 041AV (61cc) with 24”?/26”? bar. Working the Stihl gives me rubber-arms in fairly short order but I keep it because I love its unique exhaust tone. Rather than sounding like a mosquito, it kinda goes pocky-pocky-pocky.
 
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Perhaps I'm overly cautious, but I'm not 18 anymore and one thought that went into which saw to purchase was how much saw can I safely handle. There are those times when huge logs and crotches come along and need to be processed and I can't part them out with my power and bar capacity, but the great majority of the time I can process blanks to the capacity of my lathe.

In my experience, if my saw isn't cutting well, it's the chain and not a lack of power. (The darn saw just LOVES eating hidden nails and occasionally snacking on gravel :()
 

hockenbery

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Many years ago we had a super demo by a husqvarna rep.
He covered safer, saw maintenance, tuning the carberator, sharpening.

When he got to the bucking prongs he related a story of a logger who said
" bucking prongs? We call that the DCO - Dull Chain Over Ride"
 
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Dull chain override? He never did a full day of bucking logs if that is his opinion. Well that and he may have not cut anything over 12" diameter. It's a work smarter not harder technique. Drop a saw into a 24" white oak log and ignoring the bucking teeth is just plain crazy. It's simple physics and good technique to shorten the fulcrum and get better leverage with the bucking teeth. I've seen people using chainsaws like a one man buck saw. They are constantly rotating the saw and even pulling it back and forth, in and out. Why put all the effort into the saw? Those high performance speed cutters don't use the bucking teeth, but they are only cutting for a couple minutes at a time.
 
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I have two Sthil saws that rip through anything. The smaller one is an MS 391 with a 20" bar, and the other is an MS 440 Magnum with a 25" bar. I use the Magnum to rip through logs of any diameter up to 40",( Coming in from both ends) and the 391 to round the blanks. Once in a while I get larger logs and I borrow a friends 660. I use the agressive chains that have a yellow square on the box. The green ones don't cut fast enough for me. I buy 5 chains at a time from my local dealer and he gives me the sixth one free. I have a Timberline sharpening jig I like. pmk
 
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Gas can contribute to the saw not running and cutting well... Husquavarna now sells mix in a can. 95 octane clear with the mix already in it. I tried out a case of it. Normally, I would just use premium gas straight from the pump. My saw and weed whacker both ran a lot better on the higher octane clear gas. It is pretty spendy, and great if you seldom run your saw. I went to a local station that carries clear gas and tried some 92 octane clear. They still run well. They also have 97 octane which I haven't tried yet, but it runs about $7 per gallon, but may try it as well, just out of curiosity....

I do have 2 saws. One Husky with a 24 inch bar, and a Sthil with a 36 inch bar. Most of the time I use the Husky. I don't often need the 36 inch bar any more..

robo hippy
 

hockenbery

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Dull chain override? He never did a full day of bucking logs if that is his opinion.
DCO came from loggers with the six foot bars when the speaker was doing an osha class.
The speaker was relating DCO to us as a joke.

Sharp chains always work best. Like any cutting tool they begin to go from sharp to dull as we use them.
I've never had a chain that could stay sharp much past 2 tanks of gas with my Stihl 44 mag with a 24" bar. Dirt and foreign objects can dull one in an instant
 

Bill Boehme

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Gas can contribute to the saw not running and cutting well... Husquavarna now sells mix in a can. 95 octane clear with the mix already in it. I tried out a case of it. Normally, I would just use premium gas straight from the pump. My saw and weed whacker both ran a lot better on the higher octane clear gas. It is pretty spendy, and great if you seldom run your saw. I went to a local station that carries clear gas and tried some 92 octane clear. They still run well. They also have 97 octane which I haven't tried yet, but it runs about $7 per gallon, but may try it as well, just out of curiosity....

I do have 2 saws. One Husky with a 24 inch bar, and a Sthil with a 36 inch bar. Most of the time I use the Husky. I don't often need the 36 inch bar any more..

robo hippy

A bit of trivia about gasoline:
  • The energy in a gallon of 80 octane gasoline is 114,000 BTU.
  • The energy in a gallon of 90 octane gasoline is 114,000 BTU.
  • The energy in a gallon of 100 octane gasoline is 114,000 BTU.
Q: So what is the difference between the various octane ratings if they all deliver the same amount of energy?
A: The difference is the rate at which gasoline burns. The higher the octane rating, the slower it burns. With low octane gas, the spark can cause the gas in the cylinder to burn explosively especially if it is over lean ... a condition known as detonation. Detonation is hard on the engine and causes the engine to run hotter. With high octane gas, the spark causes the gas to burn slower, creating a high pressure wave front that pushes the piston down rather than hammering it down. The engine runs cooler and more of the gasoline's thermal energy gets converted into mechanical motion. So, the difference is whether energy is wasted in heating the engine or converted into useful mechanical motion. We ought not get carried away with thinking that higher octane rating is always better. There is an optimal octane rating based on the engine design and using gasoline with a higher octane rating than the optimal value doesn't provide any performance gain.

My two chainsaws don't warrant mentioning, but I'll do it anyway. I have a 30 year old gasoline Stihl 025C and a Sthil MSE170C electric saw both with 16" bars which is plenty long enough for most of the the trees that grow in the rather dry central Texas area.
 
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High compression engines need high octane, as you will get combustion before top dead center of the piston, so it will push the piston down back and this can/will cause engine damage, like broken crankshafts
High octane prevents the pre-combustion of the gasoline.
Timed fuel injection does away with this problem, as is the reason why Diesel engines have to have fuel injection.
 
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Interesting. I have never had a problem with gas in anything I owned.
I had a friend who was a chemical engineer and worked at a local refinery in Louisiana. He revealed a lot to me about the refinery. They ran many different brands of oil- even well-known brands. They would even make a brand for you- just change the label. What was more interesting, if my memory serves me, is that when the octane rating was lower than needed, they just added naphtha.
I had a 65 Corvette. Does anyone remember the Shell blended gas? You dialed the proper setting and filled up. I used the highest rated gas and my V-8 ran like a scalded cat! Yes, wish I still had it!
 
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I had a 65 Corvette. Does anyone remember the Shell blended gas? You dialed the proper setting and filled up. I used the highest rated gas and my V-8 ran like a scalded cat! Yes, wish I still had it!

I seem to recall the dial setting was at Sunoco but, you know, ...memory.

I started with a ’65 convertible in ‘78; sold that to buy a ’67 427 coupe in ’80. Still have the ’67 (added a ’72 454 in ’89). Although I’ve not changed to hardened valve guides (doesn’t get driven much) it runs fine on today’s premium 10% ethanol unleaded.
 
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and a Sthil MSE170C electric saw both with 16" bars which is plenty long enough for most of the the trees that grow in the rather dry central Texas area.

Oh. I forgot about my Makita 16" electric that sits near the lathe for quick trimming to turn easier. My turnery is in my basement and firing up a gas saw just wouldn’t go over well with the management.
 
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She was about 5-8, 130 lbs., brunette and loved to ride with the top down on summer evenings. Are we talking about the same thing? Tom, I'm at the age now where my biography would look like the Encyclopedia Britannica, printed edition. Some pages would be blank, though.:p
 
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Probably more important that octane is making sure you are not running gas with ethanol. Around here the only non ethanol gas available is premium and it's not available at every station. You can't purchase a non ethanol lower octane.
 
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Probably more important that octane is making sure you are not running gas with ethanol. Around here the only non ethanol gas available is premium and it's not available at every station. You can't purchase a non ethanol lower octane.

Unfortunately finding non-ethanol gas is not an option for most.
 

odie

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Odie,

Any time you buy an older machine you will most likely need to replace the fuel line, fuel filter, carb gasket and carb diaphragm. Expect to spend a couple hours tinkering with the machine to get it working correctly. Replace the bar and chain and you might as well purchase a new saw.
 

odie

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So you're a rider Odie? Let me guess--- Beemers?

At the moment, one Harley, and one Honda. Had a BMW w/sidecar once too!.....along with Triumphs, Kawasaki, and Suzuki.......! Been riding since I was a teenager. My son has a Harley, and we ride together. Everything bought while I still worked......couldn't afford it these days! :D

-----odie-----

IMG_1946.JPG 2009 Honda Rebel 230cc, my retirement "buzz around town" ride!
Harley.jpg
2000 FXDX 88ci......my ride! :D
Boy on the left is my son......he's now eighteen years old and rides a HD Sportster.
 
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hockenbery

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Dang, chopping firewood with a chainsaw just sounds painful and terribly inefficient.
:) Might tell you something about the quality of the saw. :)

Sounds like the guy who bought a chain saw guaranteed to cut 10 chords a day.

Takes it back back says "try as I might I can only cut 2 cords a day"
Dealer says "let's see how it runs" starts it up. The guy says "what's that sound?"
 
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Bill Boehme

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Interesting. I have never had a problem with gas in anything I owned.
I had a friend who was a chemical engineer and worked at a local refinery in Louisiana. He revealed a lot to me about the refinery. They ran many different brands of oil- even well-known brands. They would even make a brand for you- just change the label. What was more interesting, if my memory serves me, is that when the octane rating was lower than needed, they just added naphtha.
I had a 65 Corvette. Does anyone remember the Shell blended gas? You dialed the proper setting and filled up. I used the highest rated gas and my V-8 ran like a scalded cat! Yes, wish I still had it!

The octane rating was increased by increasing the amount of TEL (tetra ethyl lead). I doubt that naphtha could actually increase the octane rating. But, there are a number of things that go by the name of naphtha ... maybe not the same naphtha as the VM&P naphtha that we get at the hardware store.

Do you remember when Shell used to advertise TCP in their gasoline? TCP is tricresyl phosphate which is a lead scavenging agent which helped prevent plug fouling and pre-ignition caused by carbon deposits on the cylinder head. I used to mix it with auto gas as a lower cost substitute for 80/87 avgas in my airplane.

Leo, I'm not sure about two-cycle chainsaw engines, but in auto engines ignition is normally set to occur a few degrees prior to TDC. Pre-ignition occurs when carbon deposits on the cylinder head act as go-plugs and cause ignition far too soon. The result is knocking. Using higher octane gas won't prevent pre-ignition, but reduces the effect of knocking because of slower burning.
 
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Using higher octane gas won't prevent pre-ignition, but reduces the effect of knocking because of slower burning.

There are various additives for increasing octane. I assume that adding oil does the same.
My old Stihl 090 wanted a 30:1 mixture, back in the 70's. I presume that was with leaded gas as well.

I just had to replace the piston and cylinder, after my landscaping buddy borrowed it.
He figured these old saws just ran straight gas. Well, they do - for about 2 min.

Grrr..he wont be borrowing any of my tools from here on.
 
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Bill Boehme

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There are various additives for increasing octane. I assume that adding oil does the same.
My old Stihl 090 wanted a 30:1 mixture, back in the 70's. I presume that was with leaded gas as well.

I just had to replace the piston and cylinder, after my landscaping buddy borrowed it.
He figured these old saws just ran straight gas. Well, they do - for about 2 min.

Grrr..he wont be borrowing any of my tools from here on.

Octane rating can be increased by a number of different oxidizers such as methanol, ethanol, propanol, and f-butanol. Drag racers used nitromethane. There were some other additives that were extremely toxic. I'm doubtful that oil increases octane rating. Two-cycle engines use oil in the gas because it also serves as a lubricant since there isn't an oil sump as there is in four-cycle engines. Early two-cycle engines used a pretty rich oil mix. We had an outboard motor from about the 1930's that used an 8:1 ratio. It didn't take too long for the plug to foul. We also had 1960's era outboard motors and a chainsaw that used a 16:1 ratio. All these early engines were real smokers. It took a while for me to get used to the idea of using a 50:1 ratio after being accustomed to pouring a cup of regular motor oil in a gallon of gas. The specialized two-cycle lubricants used today are a low ash type that burn cleanly with the gas so that the plug isn't fouled nor is the cylinder gummed up.

I'm sure that there must be a special place in the hereafter for folks who borrow tools. :rolleyes: You have to ask yourself why they want to borrow your tools. The reasons that come to mind aren't very comforting:
  • They broke their tool and want to break yours as well.
  • They don't know how to use tools, but are willing to learn by trial and error while misusing yours.
  • They don't want to invest in buying tools that they know they will wind up breaking.
  • There's no clean up or maintenance when you borrow.
  • Borrowing is what friends are for.
Oh well, I know better, but I still loan tools to friends. I figure that tools can be replaced more easily than friends.
 
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Leo, I'm not sure about two-cycle chainsaw engines, but in auto engines ignition is normally set to occur a few degrees prior to TDC. Pre-ignition occurs when carbon deposits on the cylinder head act as go-plugs and cause ignition far too soon. The result is knocking. Using higher octane gas won't prevent pre-ignition, but reduces the effect of knocking because of slower burning.

Bill yes TDC is applied and automatically increased whit higher RPM in car engines, there is that need in every engine for the time it takes to get the spark, electronics make this much easier than in the old days centrifugal weights in the distributor that did this if everything worked right

But that is not what I was talking about, gasoline and diesel fuel will combust when put under high compression, so this can happen before the piston reaches TDC and you will then get damage to the engine.

To prevent this the refineries add a product that will prevent this from happening, with a diesel with their much higher compression this would make it impossible to work, that is where Mr Diesel found a way around it by injection of the fuel into the cylinder at the exact time, (a little history here, Diesel wanted to sell his invention in his native Germany, but wasn’t able to, he then went on the ferry to England, but never arrived :eek:)
The carbon glow is not present in a healthy engine, but if there it will foul the plugs though :D

I just pulled this up, that should help I think.
Octane.jpg
 
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Bill Boehme

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Gas can contribute to the saw not running and cutting well... Husquavarna now sells mix in a can. 95 octane clear with the mix already in it. I tried out a case of it. Normally, I would just use premium gas straight from the pump. My saw and weed whacker both ran a lot better on the higher octane clear gas. It is pretty spendy, and great if you seldom run your saw. I went to a local station that carries clear gas and tried some 92 octane clear. They still run well. They also have 97 octane which I haven't tried yet, but it runs about $7 per gallon, but may try it as well, just out of curiosity....

I do have 2 saws. One Husky with a 24 inch bar, and a Sthil with a 36 inch bar. Most of the time I use the Husky. I don't often need the 36 inch bar any more..

robo hippy

I was searching the Stihl website for information on my old saw and came across information about what grade of gas to use. It said to use premium gas of 90 octane or higher because the engine will run cooler. Stihl also sells premixed high octane fuel for a high octane price. I bought a can of it last year out of curiosity, but haven't tried it yet. I had forgotten about the owners manual saying to use high octane gas since I don't use the saw more than a few times a year since I quit cutting firewood many years ago.
 

Bill Boehme

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Bill yes TDC is applied and automatically increased whit higher RPM in car engines, there is that need in every engine for the time it takes to get the spark, electronics make this much easier than in the old days centrifugal weights in the distributor that did th

It has nothing at all with the time to produce a spark. It has to do with the time it takes for the fuel to build up a sufficient pressure once ignited by the spark. At very high RPM's the spark may occur as much as twenty degrees before the piston reaches TDC in order to have mostly complete combustion by the time that the exhaust port is opened.
 
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People who want to borrow tools bring this to mind:
"Could I borrow your chainsaw?"
"No. I'm making soup."
"What does making soup have to do with me borrowing your chainsaw?"
"If I don''t want to loan you the chainsaw, one reason is as good as another."
 
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